Sowing devices with coulters distributed uniformly along the sowing width for delivering agricultural materials, especially seed and/or fertilizer, into cultivated soil should ensure a uniform sowing depth/penetration depth and, after delivery of the seed/fertilizer, the pressing/closing of the furrow which is optimum for the respective seed conditions. In this case not only does the seed/fertilizer play a major part, but also the soil composition, such as for example the moisture content of the soil and mainly obstacles which are present in or on the soil, such as rocks.